Which movie star is the best investment?

Leave it to the number-crunchers at Forbes to determine which movie stars offer the biggest bang for the buck. According to the magazine’s new “Ultimate Star Payback List,” the best return on investment comes from Matt Damon (pictured), whose last three films (before The Bourne Ultimatum) grossed an average of $29 (factoring in worldwide box office and domestic DVD sales) for every dollar of his salary. Using that formula, Brad Pitt comes in at No. 2 (because of his widespread overseas appeal), Johnny Depp and Vince Vaughn tie for third (Depp for the huge gross of the Pirates movies, Vaughn for how much films like The Break-Up have grossed, relative to their low cost and his modest salary), and no. 5 is… Jennifer Aniston?

Uh, okay, I guess she deserves credit, along with Vaughn, for the success of The Break-Up, and her salary is modest by A-list leading-lady standards, but is that enough to make up for her string of flops and her inability to open a film on her own? By Forbes‘ logic, shouldn’t Pirates‘ Keira Knightley be the top actress? How useful is any list that ranks Aniston well above Tom Hanks, Tom Cruise, and Will Smith? Granted, those three actors star in big-budget movies and take big back-end cuts. In the end, though, if you’re a studio exec, you’re still not going to cut Hanks’ or Smith’s pay, and you’re going to think twice about giving Aniston a raise. Forbes‘ math could be right, could be wrong, but it’s oftencounterintuitive to what the stars are perceived to be worth, which iswhat really matters.

Similarly, shouldn’t Tobin Bell, who plays Jigsaw in the Saw movies, be Forbes‘ top actor? After all, his movies cost next to nothing and earn huge returns on their investment. Then again, the major studios aren’t in the business ofgetting the best rate of return; they’re in the business of generating the highest possible grosses. They’d rather spend $200 million togross $800 million than spend $10 million to gross $100 million. To the extent that the Forbes list bucks Hollywood’sconventional wisdom about who’s being paid what they’re worth and what kind of grosses its movies should generate, it’sgoing to be shrugged off in the executive suites.